QmlDesigner: Add visible to section

Change-Id: I7d4e3ef3fe843d28336c306afa6de0e3450eb733
Reviewed-by: Tim Jenssen <tim.jenssen@digia.com>

src/plugins/qmldesigner/components/itemlibrary/itemlibrarysection.h

@@ -40,6 +40,7 @@ class ItemLibrarySection: public QObject {
 
     Q_PROPERTY(QObject* sectionEntries READ sectionEntries NOTIFY sectionEntriesChanged FINAL)
     Q_PROPERTY(QString sectionName READ sectionName FINAL)
+    Q_PROPERTY(QString visible READ isVisible NOTIFY visibilityChanged FINAL)
     Q_PROPERTY(bool sectionExpanded READ sectionExpanded FINAL)
     Q_PROPERTY(QVariant sortingRole READ sortingRole FINAL)
 
@@ -60,6 +61,7 @@ public:
 
 signals:
     void sectionEntriesChanged();
+    void visibilityChanged();
 
 private:
     ItemLibrarySectionModel m_sectionEntries;